First Record of Hermaphroditism in Green Mussels (Perna viridis) in the Philippines

This paper reports an incidence of hermaphroditism in green mussel (Perna viridis) in Inner Malampaya Sound, Taytay Palawan, Philippines, through histology. One hermaphrodite specimen (0.18% of the total samples) was recorded. The sample was macroscopically classified as a male. However, histology showed the presence of both male and female gametes inside the gonad with the dominance of male gametes. The total male to female (1:0.86) sex ratio in this study was statistically different (P = 0.002) from the expected binomial distribution of the 1:1 sex ratio. Despite its currently low occurrence, hermaphroditism in green mussels could have significant effects on reproduction, population dynamics, and aquaculture if its incidence increases in the future.